A Finite Element Model for Ultrasonic Cutting of Toffee

2006 ◽  
Vol 5-6 ◽  
pp. 519-526 ◽  
Author(s):  
E. McCulloch ◽  
Alan MacBeath ◽  
Margaret Lucas
Keyword(s):  
Finite Element ◽  
Failure Criterion ◽  
Uniaxial Tensile ◽  
Test Machine ◽  
Fe Model ◽  
Temperature Dependent ◽  
Erosion Model ◽  
Element Erosion ◽  
Element Removal ◽  
Ultrasonic Cutting

The performance of an ultrasonic cutting device critically relies on the interaction of the cutting tool and the material to be cut. A finite element (FE) model of ultrasonic cutting is developed to enable the design of the cutting blade to be influenced by the requirements of the toolmaterial interaction and to allow cutting parameters to be estimated as an integral part of designing the cutting blade. In this paper, an application in food processing is considered and FE models of cutting are demonstrated for toffee; a food product which is typically sticky, highly temperature dependent, and difficult to cut. Two different 2D coupled thermal stress FE models are considered, to simulate ultrasonic cutting. The first model utilises the debond option in ABAQUS standard and the second uses the element erosion model in ABAQUS explicit. Both models represent a single blade ultrasonic cutting device tuned to a longitudinal mode of vibration cutting a specimen of toffee. The model allows blade tip geometry, ultrasonic amplitude, cutting speed, frequency and cutting force to be adjusted, in particular to assess the effects of different cutting blade profiles. The validity of the model is highly dependent on the accuracy of the material data input and on the accuracy of the friction and temperature boundary condition at the blade-material interface. Uniaxial tensile tests are conducted on specimens of toffee for a range of temperatures. This provides temperature dependent stress-strain data, which characterises the material behaviour, to be included in the FE models. Due to the difficulty in gripping the tensile specimens in the test machine, special grips were manufactured to allow the material to be pulled without initiating cracks or causing the specimen to break at the grips. A Coulomb friction condition at the bladematerial interface is estimated from experiments, which study the change in the friction coefficient due to ultrasonic excitation of a surface, made from the same material as the blade, in contact with a specimen of toffee. A model of heat generation at the blade-toffee interface is also included to characterise contact during ultrasonic cutting. The failure criterion for the debond model assumes crack propagation will occur when the stress normal to the crack surface reaches the tensile failure stress of toffee and the element erosion model uses a shear failure criterion to initiate element removal. The validity of the models is discussed, providing some insights into the estimation of contact conditions and it is shown how these models can improve design of ultrasonic cutting devices.

scholarly journals 3D-Finite element modeling of lead rubber bearing using high damping material

2019 ◽  
Vol 276 ◽  
pp. 01013
Author(s):  
Ahmad Basshofi Habieb ◽  
Tavio Tavio ◽  
Gabriele Milani ◽  
Usman Wijaya
Keyword(s):  
Finite Element ◽  
Shear Behaviour ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Fe Model ◽  
Rubber Material ◽  
Isolation System ◽  
Cyclic Shear ◽  
Rubber Bearing ◽  
Lead Rubber Bearing

Lead Rubber Bearing (LRB) has been widely applied for seismic protection of mid and high-rise buildings around the world. Its excellent energy dissipation becomes the most important aspect of this isolation system thanks to the plasticity and recovery behavior of the lead core. Aiming to develop a deeper knowledge on the behavior of LRB’s, a 3D detailed finite element (FE) modeling is performed in Abaqus FE software. Some important parameters involved in the model are plasticity of the lead core and hyper-elasticity and viscosity of the rubber material. The parameters for rubber material are derived from the results of experimental works in the laboratory, including uniaxial tensile test and relaxation test. The bearing model is then subjected to a cyclic shear-test under constant vertical load. The result of the 3D-FE model is then compared with the analytic-Abaqus model for LRB isolators, developed in the literature. Finally, both 3D-FE model and analytic model result in a good agreement on the shear behaviour of the presented LRB.

FEM-Based Simulation of Temperature in Speed Stroke Grinding with 3D Transient Moving Heat Sources

2011 ◽  
Vol 223 ◽  
pp. 733-742 ◽  
Author(s):  
Barbara Linke ◽  
Michael Duscha ◽  
Anh Tuan Vu ◽  
Fritz Klocke
Keyword(s):  
Finite Element ◽  
Material Properties ◽  
Material Removal ◽  
Structural Changes ◽  
Numerical Technique ◽  
Temperature Fields ◽  
Fe Model ◽  
Measured Temperature ◽  
Temperature Dependent ◽  
Removal Rates

The grinding process is one of the most important finishing processes to obtain high surface quality. Nowadays, grinding is also considered as a high performance process with high material removal rates. Nevertheless, to avoid thermally-induced structural changes poses a major challenge for this manufacturing technology. Until now, the Finite Element Method (FEM) has been widely applied as a proper numerical technique to predict workpiece properties in machining processes. However, actual models in grinding are limited to conventional grinding processes with simple workpiece profiles and low table speeds. In this paper, finite element simulations are expanded to 3-dimensional (3D) models with temperature-dependent material properties and heat source profiles derived from experimental results, i.e. tangential forces. Both temperature simulation and measurement were conducted for deep grinding, pendulum grinding and speed stroke grinding in the table speed range of vw= 12 m/min to 180 m/min and specific material removal rates of Q’w= 40 mm³/mms. Overall, the simulation results show a good agreement with the measured temperature and surface integrity after grinding. This research indicates that a 3D FE model with temperature dependent material properties can predict realistic temperature fields in speed stroke grinding. Therefore, the experiment and measurement costs and time can be reduced by FEM simulation.

Viscoelastic Finite Element Modeling of Bimodal High Density Polyethylene (HDPE) Piping Materials for Nuclear Safety-Related Applications

2010 ◽  
Author(s):  
Do-Jun Shim ◽  
Prabhat Krishnaswamy ◽  
Yunior Hioe ◽  
Sureshkumar Kalyanam
Keyword(s):  
Finite Element ◽  
Service Life ◽  
High Density Polyethylene ◽  
Viscoelastic Behavior ◽  
Time Dependent ◽  
Tensile Creep ◽  
Uniaxial Tensile ◽  
Fe Model ◽  
Creep Tests ◽  
Uniaxial Tensile Creep

The U.S. Nuclear Regulatory Commission (USNRC) has recently approved Relief Requests for the use of high density polyethylene (HDPE) piping in safety-related applications. The ASME Boiler and Pressure Vessel Code, meanwhile, has developed Code Case N-755 that defines the design and service life requirements for PE piping in nuclear plants though it has not as yet been approved by the USNRC. One of the issues of concern is premature failure of PE piping due to slow crack growth (SCG) that can initiate due to a combination of sustained loads, elevated temperatures, and a pre-existing defect. Understanding and predicting the SCG behavior is an essential step in developing a methodology for predicting the service life of PE piping. The first step in studying the failure process in a polymer under a constant sustained load is the selection of a suitable constitutive model to represent the time-dependent behavior of the material. In this paper, uniaxial tensile creep tests were performed for a bimodal HDPE (PE4710) piping material. This creep data was used to determine the viscoelastic material constants for this bimodal HDPE using a power-law creep model. These material constants were used in finite element (FE) analyses to study the viscoelastic behavior of the bimodal HDPE. As a first step, the FE model was verified by comparing the results from numerical simulations and experiments for a set of uniaxial tensile creep tests. The FE model was then applied to study the viscoelastic behavior of a SCG specimen. The time dependent stress and strain fields were investigated.

Evidence of thermoplastic instability about segmented chip formation process for Ti–6Al–4V alloy based on the finite-element method

2011 ◽  
Vol 225 (6) ◽  
pp. 1407-1417 ◽  
Author(s):  
G Chen ◽  
C Ren ◽  
X Yang ◽  
T Guo
Keyword(s):  
Finite Element ◽  
Formation Mechanism ◽  
Failure Criterion ◽  
Formation Process ◽  
Chip Formation ◽  
Deformation Zone ◽  
Chip Morphology ◽  
Fe Model ◽  
Friction Characteristic ◽  
Segmented Chip

A ductile failure law and an energy-based failure criterion have been implemented in a 2D finite-element (FE) model to simulate the segmented chip formation process in titanium alloy (Ti–6Al–4V) machining. The variations of stress and strain are taken into account in defining the material failure criterion. The cutting forces and chip morphology calculated by FE model are compared with experimental results in good agreement, validating the FE model. Stresses, strains, cutting temperatures, and stiffness degradation along adiabatic shear bands (ASBs) are analysed during the segment formation process to investigate the segment formation mechanism. It is found that the variation trend of strains is the same as that of temperatures, in addition, the variation of strains and their changing-rate lag slightly behind those of temperatures. These observations provide a new evidence of thermoplastic instability along ASB and increase the understanding of segmented chip formation mechanism. Furthermore, simulation results show that ASB morphology and its forming mechanism are mainly caused by thermoplastic instability in primary deformation zone and friction characteristic in the second deformation zone.

Finite Element Analysis of Buried Polyethylene Pipe Subjected to Seismic Landslide

2014 ◽  
Vol 136 (3) ◽  
Author(s):  
Xiangpeng Luo ◽  
Jinjin Ma ◽  
Jinyang Zheng ◽  
Jianfeng Shi
Keyword(s):  
Finite Element ◽  
Failure Criterion ◽  
Urban Areas ◽  
Deformation Behavior ◽  
Transportation Systems ◽  
Uniaxial Tensile ◽  
Seismic Load ◽  
Pipe Length ◽  
Quartic Polynomial ◽  
Seismic Landslide

Polyethylene (PE) pipes are widely used in natural gas transportation systems in urban areas nowadays. As landslide caused by earthquake would cause destructive damage to buried pipes, increasing attention is attracted to the safety of buried PE pipes under seismic load. In this paper, the deformation behavior of PE pipe subjected to seismic landslide was investigated and a related failure criterion due to yielding was proposed. Based on extensive uniaxial tensile tests, a rate-dependent constitutive model of PE was applied to simulate the mechanical behavior of PE pipes. The extended Drucker-Prager model was used for surrounding soil. In our proposed finite element model, a quartic polynomial bending deflection displacement normal to the pipeline was loaded along the axial direction of PE pipe. The numerical simulation results revealed that the main failure mode of buried PE pipe subjected to seismic landslide shifted from bending deformation to ovalization deformation with increasing bending deflection. On the basis of deformation behavior analysis, failure criterion curves were put forward, which depicts the maximum relative deflection of the pipe cross-section, and the maximum displacement of the pipe versus pipe length subjected to seismic landslide. The results may be referable for design and safety assessment of PE pipes due to seismic landslide.

Parameters Determination of Mooney-Rivlin Model for Rubber Material of Mechanical Elastic Wheel

2017 ◽  
Vol 872 ◽  
pp. 198-203 ◽  
Author(s):  
Xian Bin Du ◽  
You Qun Zhao ◽  
Fen Lin ◽  
Zhen Xiao
Keyword(s):  
Finite Element ◽  
Tensile Tests ◽  
Driving Safety ◽  
Uniaxial Tensile ◽  
Test Machine ◽  
Rubber Material ◽  
Material Parameters ◽  
Elastic Wheel ◽  
Mechanical Elastic Wheel ◽  
The Stability

In order to improve the driving safety of vehicles, a non-pneumatic safety tire named mechanical elastic wheel was developed, and the structural components of mechanical elastic wheel and the method of determining the rubber material parameters of Mooney-Rivlin model were introduced. Uniaxial tensile tests of the rubber in different parts of mechanical elastic wheel were carried out with a stretch test machine and the material parameters and of the Mooney-Rivlin model were determined by fitting the experimental data. Finite element method (FEM) was used to validate the stability of the fitted data. The results show that the obtained material parameters have high accuracy and can be a reference for the subsequent finite element simulation of mechanical elastic wheel.

Finite Element Modeling of Deformation Behavior of Steel Specimens under Various Loading Scenarios

2015 ◽  
Vol 651-653 ◽  
pp. 969-974 ◽  
Author(s):  
Dilip Banerjee ◽  
Mark Iadicola ◽  
Adam Creuziger ◽  
Tim Foecke
Keyword(s):  
Finite Element ◽  
Deformation Behavior ◽  
Stress Measurement ◽  
High Strength Steels ◽  
High Strength ◽  
Tensile Tests ◽  
Image Correlation ◽  
Uniaxial Tensile ◽  
Fe Model ◽  
Strain Paths

Lightweighting materials (e.g., advanced high strength steels, aluminum alloys etc.) are increasingly being used by automotive companies as sheet metal components. However, accurate material models are needed for wider adoption. These constitutive material data are often developed by applying biaxial strain paths with cross-shaped (cruciform) specimens. Optimizing the design of specimens is a major goal in which finite element (FE) analysis can play a major role. However, verification of FE models is necessary. Calibrating models against uniaxial tensile tests is a logical first step. In the present study, reliable stress-strain data up to failure are developed by using digital image correlation (DIC) technique for strain measurement and X-ray techniques and/or force data for stress measurement. Such data are used to model the deformation behavior in uniaxial and biaxial tensile specimens. Model predictions of strains and displacements are compared with experimental data. The role of imperfections on necking behavior in FE modeling results of uniaxial tests is discussed. Computed results of deformation, strain profile, and von Mises plastic strain agree with measured values along critical paths in the cruciform specimens. Such a calibrated FE model can be used to obtain an optimum cruciform specimen design.

scholarly journals Reduction of Residual Stress for High-Strength Low-Alloy Steel Strip Based on Finite Element Analysis

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Zengshuai Qiu ◽  
Anrui He ◽  
Jian Shao ◽  
Xiaoming Xia
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Boundary Conditions ◽  
Alloy Steel ◽  
Steel Strip ◽  
High Strength ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Fe Model ◽  
Low Alloy Steel

Intensive cooling technology is widely utilized in the production of high-strength hot-rolled steel strip. However, intensive cooling at high cooling rate may cause stress heterogeneity on a steel strip, which further generates great residual stress and influences steel strip shape. In this study, a three-dimensional finite element (FE) model of high-strength low-alloy steel strip on the run-out table coupled with heat transfer, phase transformation, and strain/stress is developed by ABAQUS software. To enhance modeling precision, several experiments are conducted, such as uniaxial tensile test at multiple temperatures, dynamic continuous cooling transformation, and scanning electron microscopy, to determine the material properties and boundary conditions of the FE model. Four new models are established based on this model to reduce the residual stress of strip by modifying the initial and boundary conditions. Results show that reducing the initial transverse temperature difference is the most effective in reducing residual stress, followed by sparse cooling, edge masking, and posterior cooling.

scholarly journals A finite element and experimental analysis of durability tested springs

2018 ◽  
Vol 165 ◽  
pp. 03017 ◽  
Author(s):  
Ying Wang ◽  
Constantinos Soutis ◽  
Lorenzo Gagliardi
Keyword(s):  
Finite Element ◽  
Experimental Analysis ◽  
Structural Integrity ◽  
Mechanical Tests ◽  
Test Machine ◽  
Fe Model ◽  
Original Design ◽  
Fe Simulations ◽  
Corrosion Pits

Ageing of vehicles has become a major concern as the vehicles reach the end of their original design life. Corrosion is part of long-term ageing and forms one of the critical degradation processes affecting the mechanical properties, such as stiffness, affecting the structural integrity and life of key components. In this study, a finite element and experimental analysis was carried out to investigate the response of corroded springs in relation to the morphology of a corroded surface. An FE model was created using ABAQUS that correlates the stiffness changes with ageing. The analysis of corrosion-induced stress is then performed to determine the stress fields within the corrosion region. The durability tested springs were analysed with a microscope to identify the morphology of corrosion pits; the measured pattern was adopted in the subsequent FE simulations. A spring test machine was employed to perform the mechanical tests. The load-deflection behaviour of durability tested springs was recorded and then was used to validate the FE simulations.

scholarly journals Finite element model and experimental studies on rubber-cord composite

2007 ◽  
Vol 29 (4) ◽  
pp. 551-561 ◽  
Author(s):  
Tran Huu Nam
Keyword(s):  
Finite Element ◽  
Experimental Studies ◽  
Element Model ◽  
Tensile Tests ◽  
Rubber Matrix ◽  
Uniaxial Tensile ◽  
Fe Model ◽  
Material Behaviour ◽  
Mechanical Responses ◽  
Cyclic Tension

The rubber-cord composite (CRC) which is created of rubber matrix reinforced with textile cords is used for many applications such as pneumatic membranes, automobile tires, pneumatic air-springs, hydraulic hoses and many others. The CRC is characterized by strongly anisotropic material behaviour and can simultaneously undergo large elastic deformations. In this paper a finite element (FE) model was developed and applied to study the mechanical responses of CRC. This model consists of 8-node hexahedral brick elements describing rubber matrix and 3-D spar elements for modeling of textile cords. The experimental studies in uniaxial and cyclic tension were performed. The material constants of textile cords were fitted to experimentally measured data by approach technique using linear and bilinear elastic models. The simulations of uniaxial tensile tests using proposed FE model were carried out. The numerical results of simulations were compared to experimental ones in order to verify the accurateness of the FE model. The obtained results indicated that the proposed FE model can be applied for the modeling and simulation of mechanical behaviour of CRC.

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